First Results of ${\nu }_e$ Appearance Analysis and Electron Neutrino Identification at NOvA

Abstract

NOvA is a long-baseline accelerator-based neutrino oscillation experiment that is optimized for ${\nu }_{\mu }\to {\nu }_e$ measurements. It uses the upgraded NuMI beam from Fermilab and measures electron-neutrino appearance and muon-neutrino disappearance at its Far Detector in Ash River, Minnesota. The ${\nu }_e$ appearance analysis at NOvA aims to resolve the neutrino mass hierarchy problem and to constrain the CP-violating phase. The first data set of $2.74\times 10^{20}$ protons on target (POT) equivalent exposure taken by NOvA has been analyzed. The first measurement of electron-neutrino appearance in NOvA provides solid evidence of ${\nu }_{\mu }\to {\nu }_e$ oscillation with the NuMI beam line. Electron-neutrino identification is the key ingredient for the ${\nu }_e$ appearance analysis. The electron-identification algorithm used to produce the primary results presented here compares 3-D shower-energy profiles with Monte Carlo prototypes to construct likelihoods for each particle hypothesis. Particle likelihoods, among other event-topology variables, are used as inputs to an Artificial Neural Network for the final electron-neutrino identification. The design and implementation of this algorithm is also presented.

Presentation at the DPF 2015 Meeting of the American Physical Society Division of Particles and Fields, Ann Arbor, Michigan, August 4-8, 2015

Cited by in corpus (5)

• First measurement of electron neutrino appearance in NOvA
• Observation of Energy and Baseline Dependent Reactor Antineutrino Disappearance in the RENO Experiment
• Improved Energy Reconstruction in NOvA with Regression Convolutional Neural Networks
• Reason for T2K to run in dominant neutrino mode for detecting CP violation
• The remnant CP transformation and its implications